I was director of the Centre of Mathematics for Applications CMA since the start in 2003 to 2013. CMA was one of the first thirteen Norwegian centres of excellence supported by the Research Council of Norway. From 2004 to 2010 I was serving as chairman of the board of the Niels Henrik Abel Memorial Fund.

My research interests are partial differential equations and numerical analysis. In particular, lately I have focused on the development of compatible discretization methods , in particular on finite element exterior calculus.

The scattered data interpolation problem in two space dimensions is formulated as a partial differential equation with interpolating side conditions. The system is discretized by the Morley finite element space. The focus of this paper is to study preconditioned iterative methods for the corresponding discrete systems. We introduce block diagonal preconditioners, where a multigrid operator is used for the differential equation part of the system, while we propose an operator constructed from thin plate radial basis functions for the equations corresponding to the interpolation conditions. The effect of the preconditioners are documented by numerical experiments.

Tveito, Aslak & Winther, Ragnar (1996). On the rate of convergence to equilibrium for a system of conservation laws including a relaxation term. SIAM Journal on Mathematical Analysis.
ISSN 0036-1410.
28:1, s 136- 161